This invention relates to a device for reducing the level of noises arising from an undercarriage of a track-type vehicle.
As is well known, noises arise from an undercarriage of a track-type vehicle equipped with track chains. The noises are considered to arise between the teeth of the sprocket and bushings interconnecting the track links, between the rolling surfaces of the idler and the track links, and between the rolling surface of the carrier roller and the track links. The noises are so-called metal-to-metal contacting noises which result from impact of one metal member upon another and can be attributed in part to vibrations in the track chain when it is slackened. Hitherto, many attempts have been proposed to eliminate the metal-to-metal contact. In one example, rubber pads are secured to the sides surfaces of a sprocket or the flange surfaces of a carrier roller or an idler for providing for the contact with the track links, i.e., rubber pads are imposed between metal contacting surfaces, thereby absorbing or moderating impact sounds. However, these attempts suffer from premature damage or wear of the rubber pads themselves because the rubber pads have to contact movable portions of track links and the like and thus the rubber pads provide a short service life. In addition, the provision of the aforesaid rubber pads leads to a need to modify the construction of the undercarriage and hence poses an economical problem.
The present invention is directed to avoiding the aforesaid shortcomings in the prior art by providing a noise reduction device for use in an undercarriage of a track-type vehicle which provides a long service life and high reliability and allows the attachment of the device to a conventional track-type vehicle with minimized modification.
According to the present invention, there is provided a noise reduction device for a track chain of a track-type vehicle, said track chain having a plurality of links pivotally connected together in an endless train and a plurality of track shoes connected to the links. Each track shoe has a back side. The noise reduction device comprises a spring connected to the back sides and is of a construction sufficient for applying an elastic resistance to pivotal movement of respective pairs of adjoining links.